The present invention relates generally to nanocomposites, and more particularly to nanocomposite concentrate materials.
Reactor grade polymers, such as for example thermoplastic olefins (TPO), are relatively flexible, and are generally less expensive than other (e.g. compounded) grades of polymers which have been modified from the reactor grade to exhibit desired mechanical, physical and/or chemical properties. For example, reactor grade polymers such as TPOs may typically be $0.20/pound less expensive than compounded grades.
Reactor grade TPOs may be used, for example, on automotive bumper fascias. This reactor grade TPO is kept in large inventory silos at the molding facility. However, body side molding is generally required to be stiffer than bumpers, and thus the molding facility keeps a separate silo of a stiffer grade of TPO. As can be appreciated, depending upon the part to be molded, the molding facility may have to keep a great number of large inventory silos or containers, each having a different grade of polymeric material therein.
Highly efficient nano particle fillers have been developed which can be compounded with thermoplastics to improve physical properties at less than 6% by weight in place of 20–30% conventional mineral fillers such as talc. However, currently, the nano particle fillers are added directly into the base thermoplastic material. The base thermoplastic material with the nano particle filler material is then compounded (which involves blending, re-melting and mixing) and repelletized to form nano particle filled pellets. The extra compounding and pelletizing step is performed in order to substantially achieve a consistent filler level. This extra compounding step is similar to an additional compounding process step used with conventional 20–30% mineral (talc, calcium carbonate, etc.) filled thermoplastics. As such, nano fillers have not as yet proven cost effective enough to utilize on a regular basis.